Drop accidentally-duplicated copy of the --diff-mask tests.

Double the test coverage!

tests/test_exclude_substrings.py

-# -*- coding: utf-8 -*-
-#
-# diffoscope: in-depth comparison of files, archives, and directories
-#
-# Copyright © 2020 Chris Lamb <lamby@debian.org>
-#
-# diffoscope is free software: you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation, either version 3 of the License, or
-# (at your option) any later version.
-#
-# diffoscope is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with diffoscope.  If not, see <https://www.gnu.org/licenses/>.
-
-import os
-import re
-import pytest
-
-from diffoscope.main import main
-
-
-def run(capsys, *args):
-    with pytest.raises(SystemExit) as exc:
-        main(
-            args
-            + tuple(
-                os.path.join(os.path.dirname(__file__), "data", x)
-                for x in ("test1.tar", "test2.tar")
-            )
-        )
-
-    out, err = capsys.readouterr()
-
-    assert err == ""
-
-    return exc.value.code, out
-
-
-def test_none(capsys):
-    ret, out = run(capsys)
-    # Make sure the output doesn't contain any [filtered]
-    assert re.search(r"\[filtered\]", out) is None
-    assert ret == 1
-
-
-def test_all(capsys):
-    ret, out = run(capsys, "--diff-mask=.*")
-
-    # Make sure the correct sections were filtered
-    assert "file list" not in out
-    assert "dir/link" not in out
-
-    # Make sure the output contains only [filtered]
-    # Lines of content start with "│ ", and then either have a +, a - or a space
-    # depending on the type of change
-    # It should then only contain "[filtered]" until the end of the string
-    assert re.search(r"│\s[\s\+\-](?!(\[filtered\])+)", out) is None
-    assert ret == 1
-
-
-def test_specific(capsys):
-    ret, out = run(capsys, "--diff-mask=^Lorem")
-    # Make sure only the Lorem ipsum at the start of the line was filtered
-    assert "[filtered] ipsum dolor sit amet" in out
-    assert '"Lorem ipsum"' in out
-    assert ret == 1